Circular knitting machine and method of knitting a tubular envelope over a flexible hose

ABSTRACT

A circular knitting machine including means for neutralizing the torque normally imparted to the hose due to the unidirectional knitting of yarns under tension directly on to the hose.

United States Patent 1191 Greczin Sept. 25, 1973 [5 CIRCULAR KNITTING MACHINE AND 3,257,828 6/1966 Greczin 66/9 A METHOD OF KNITTING A TUBULAR 226,038 3/1880 Cowen 156/393 3,516,268 6/1970 Foreman 1 66/149 R ENVELOPE OVER A FLEXIBLE HOSE 2,459,688 1/1949 De Vtver 66/147 x [76] Inventor: John J. Greczin, 7312 School Ln., 59,536 8 Simo 139/126 X philaddphia p 1912 2,752,952 7/1956 Dauphinais 66/9 A 2,468,870 5/1949 Eskow 66/9 A [22] Filed: Mar. 31, 1972 [21] Appl. No.: 240,123 Primary Examiner-James Kee Chi Att0rneyLouis Necho [52] US. Cl. 66/9 A, 66/147 R, 66/149 R [51] Int. Cl D04b 9/44 57 ABSTRACT [58] Field of Search 66/9 A, 147 R, 149 R,

66/149 5; 38/123426; 139/13 R; 156/393 A clrcular kmttmg machme 1nclud1ng means for neutralizing the torque normally imparted to the hose due 56] References Cited to the unidirectional knitting of yams under tension di- UNITED STATES PATENTS may the 2.201905" 5/1940 Larkin 66/9 A 2 Claims, 2 Drawing Figures CIRCULAR KNITTING MACHINE AND METHOD OF KNITTING A TUBULAR ENVELOPE OVER A FLEXIBLE HOSE BACKGROUND A hose made of rubber, synthetic plastics, and the like, has a limited burst strength and its use is limited to the transmission of fluids under moderate pressures. For industrial uses which involve high pressures, the hose is reinforced by knitting a tubular envelope directly on to the hose. This produces the desired reinforcement but, the unidirectional knitting of the reinforcing yarns in the form of a tubular envelope tightly hugging the hose, imparts a torque which causes the covered hose to twist and warp when it is unrestrained.

The main object of this invention is to produce an adequately reinforced hose which, when unrestrained, will lay flat and relaxed.

THE INVENTION The invention provides for initially knitting the successive courses of the tubular envelope onto a sleeve which tapers slightly, in the direction of the knitting and from which the stitches .slide off onto the hose which moves past the knitting line through said sleeve; the sleeve meanwhile being rotated in a direction opposite to the direction of knitting and at a rate calculated to neutralize the torque produced by the unidirectional spiralling of the successive courses.

IN THE DRAWINGS FIG. 1 is a fragmentary elevational view of a conventional circular knitting machine which is capable of knitting a tubular envelope over a hose, and which has been modified to embody my invention.

FIG. 2 shows the parts slightly enlarged and some of them are shown in exploded perspective.

The machine illustrated is of the type shown in my prior U.S. Pat. No. 3,543,280 which knits the tubular envelope (30) over a hose (32) which moves upwardly relative to the knitting line as indicated by the arrow in FIG. 1 of said patent. This type of machine is also shown in Larkin U.S. Pat. No. 2,201,905 except that in this patent the hose moves downwardly which, as far as this invention is concerned, is immaterial. Since the machine and its operation are well known, and form no part of this invention, it is thought unnecessary to describe the machine in detail. It is thought enough to say that the hose 30 to be covered is drawn upwardly through the machine past the knitting line to receive the knit covering.

To carry out the present invention, I mount a sleeve 33 in bearings 34, and I draw the hose 30, upwardly through the sleeve, by the take-up mechanism shown in FIG. 1. Sleeve 33 is roatated by means of a belt and pulley assembly which is actuated by a motor M. Sleeve 33 is rotated at the same R.P.M. as the needle actuating cam ring but in a direction opposite to the direction of rotation of the cam ring to neutralize the torque which was imparted to the hose by the unidirectional spiralling of the courses forming the tubular envelope.

Conventionally, the envelope is knit directly, onto the hose, and the tension under which the yarns are knit is transmitted directly to the hose. According to my invention, I provide the upper end of sleeve 33 with an extention 36 which spans the knitting line and on which the stitches of successive courses of the tubular envelope are formed and from which the stitches are transferred onto the hose. In order to facilitate transfer of the stitches from extention 36 to the hose, extention 36 is tapered slightly in the direction of the movement of the hose. The initial formation of the courses on tapered extention 36 dissipates at least a substantial portion of the torque which would otherwise be imparted to the hose, and the rotation of sleeve 33 neutralizes most, if not all, the remaining torque, so that a hose covered according to my invention will lay flat and relaxed. Extention 36 can also be made integral with sleeve 33.

What I claim is:

l. A circular knitting machine adapted to knit a tubular cover over a hose moving past the knitting line of the machine, said machine including:

a needle cylinder,

knitting needles carried by said cylinder and reciprocable in a path parallel to the axis of said cylinder, a source of yarn under tension, a cam ring rotatable about the axis of said cylinder and engageable with said needles, 7

means for rotating said cam ring at a predetermined R.P.M. to knit said yarn onto said hose, whereby a torque is imparted to the hose,

a rotary sleeve through which said hose approaches the knitting line, and

means for rotating said sleeve at the same R.P.M. as

said cam ring, but in a direction opposite the direction of rotation of said cam ring.

2. The machine of claim 1 wherein the upper end of the sleeve adjacent the knitting line is tapered in the direction of knitting whereby stitches formed on said upper end will slide easily onto the hose as it emerges from said sleeve. 

1. A circular knitting machine adapted to knit a tubular cover over a hose moving past the knitting line of the machine, said machine including: a needle cylinder, knitting needles carried by said cylinder and reciprocable in a path parallel to the axis of said cylinder, a source of yarn under tension, a cam ring rotatable about the axis of said cylinder and engageable with said needles, means for rotating said cam ring at a predetermined R.P.M. to knit said yarn onto said hose, whereby a torque is imparted to the hose, a rotary sleeve through which said hose approaches the knitting line, and means for rotating said sleeve at the same R.P.M. as said cam ring, but in a direction opposite the direction of rotation of said cam ring.
 2. The machine of claim 1 wherein the upper end of the sleeve adjacent the knitting line is tapered in the direction of knitting whereby stitches formed on said upper end will slide easily onto the hose as it emerges from said sleeve. 